Spark-plug.



H. N. ESTMAN.

SPARK PLUG;

APPLlc/mofa FILEGYAUGA. 1915 1,232126'5e Patented Aug. 14,1917.

i enr-ion HARK? Tl. EASTB/m, F BATSET, QE, SSIGNOR, BY DIRECT AND MESNE ASSIGN- MENTS, '3D0 THE L FRENCH .PVTER SBLBK PLUG COMPANY, OF COLUMBUS, OHIO,

` Lgigaga speeeation 0; Letters Patent.

remitted Aug. i4, 1ere'.

lpllcatien ii'le August (l, i935. Serial No. 43,6%.

To all fwwm it may concern: K

Be it known that l, Hanny rl. Erlernen,

lcitizen of the United States, residing at Dayton? in the county of Montgomery and State of Ohio, have invented certain new and use ful improvements in Sp:eck-Plugs7 ci which the following yis a speciication. i

My invention relates te explosive engines and more particularly to ignition or spark plugs therefor. i The object ci tbe invention is te simplify the structure as Well as the means and inode of operation of such devices whereby they will -not only be clieapened in eonstruction, but will be more etiicient in use, capable of being easily and quickly assembled and (lisu assembled, compression tight, and unlikely to get out of repair. i l/Vitii the above primary and other incidental objects in View9 as will rnoreiull appearl in the speciiication, the invention consists of the features of construction, the parte and combinations thereof7 the mode ci' i eperaton, or their equiffalents7 as hereinafter described and set forth in the claims.

Referring to the drawings, Figure 5. is a lside elcvatien of the assembled spark plug.

Fig. 2 is a longitudinal sectional View thereof. Fig. 3 is a bottom plan View thereof.

Like parts are indicated by similar cliaracters of reference throughout the several views.

ln ,the drawings l is tbe main bushing comprising a hexagonal liead having ascrew threaded extension 2 adapted to be secured in the Wall or' the engine cylinder or ignition chamber thereof. The innerl end of the p bushing or tb at end ccnnnunicating with the I materiale united tlierewiri cyli-V der or ignition eliarnber is counter boretl to form therein a seat or shoulder inserted n'i'liin the bushing from. innerA or screw 'threaded end tliereeis a core of, eff-faciale? levaiire clayg or seme similar mi lne imetallic s `method is to mold and bake the gcore il Within the Jacket at the time of manufacture, whereby said parts become substantiallyintegral. The metallic reinforcing acket 5 is provided at one end with a bearing shoulder or flange 6 adapted to coperate with the bearing seat 3 in the inner end of the main bushing.

The opposite edge of the metallicjacket 5 is screw threaded, as indicated at 7, to receive an adjusting nut 8 'which bears upon the upper end of the main bushing 1 and by its adjustment tends to draw the jacketed core upward Within the main bushing to more firmly seat the bearing shoulder 6 upon the seat 3. A gasket 9 of packing material,

preferably asbestos is introduced interme-- vdlate the bearin shoulder 6 and the seat 3.

This packing material is compressed by the adjustment ci the nut 8 to insure a joint.

immediately below the bearing shoulder or flange 6 of the reinforcing jacket the core 4 is expanded to form a truncated conical head 10. Extending through'the core e is an electrode ll having at its inner end a terminal head l2 of enlarged cylindrical shape. This provides a sparking terminal of large area and reduces the tendency to corrode and pit. The jacketed core e extends somewhat above the level of the adjusting nut 8 and is surrounded by a sleeve 13 of bard rubber, fiber, or other insulating material which rests at its lower end upon the face of the adjusting nut 8.' At its upper end the shank of the electrode ll is screw threaded and carries thereon an adjustable compression collar or disk i4 which is adjusted to bear tightly upon a sleeve 13. Above the compression disk 14 there is carried the usual binding nut l5 whichl also serves as a lock nut for the disk 14. lren jecting from the lower end of the main busligas tight v ing l is a second terminal or electrode '16,

the lower end ci which is turned laterally and is flattened into a triangular foot 1.7. The terminal edge of the foot 17 extends in a tangential direction in relation With the cylindrical iiead 12 of the electrode l1 but fio spaced away therefrom. The angular form of the foot 17 provides two sparking points 18 18 which insures a broad fat spark.

It is to be noted that/in lieu of the usual construction in which the joints between the core and .bushing-roi' housing are necessarily arranged to resist the pressure of the eXplosive charge, in the present instance the relation of the parts is reversed and the core is introduced from the inner end of the bushing and the joint so arranged that instead of t-he pressure of the explosive charge tending to open the joint the said pressure is utilized in the present instance to more firmly seat the core upon the main bushing thereby pressing the packing material to greater degree. The pressure of the explosive charge isgthereby utilized to more se cui-ely seal the joint against leakage. Spark and a new jacketed core may be easily inserted thereby renewing the spark plug at slight expense.

From the above description it Will be apparent that there is 'thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable but which obviously is susceptible of modiication in its form, proportion, detail construction, or arrangement of parts without departing from the principle involved or sacriiicing any of its advantages.

While in order to comply With the statute the invention has been described in language more or less specific as to certain structural features, it is to be understood that the invention is not limited to any speciic details but that the means and construction herein described comprise but one mode of and the invention is therefore claimed broadly in any of its possible forms or modifications Within the scope of the appended claims.

Having thus described my invention, I claim: i i

In a spark plug, a main bushing, a separable core of insulating material, a metallic jacket secured upon said core, a shoulder upon said metallic jacket engaging the inner end of the main bushing, a clamp nut screw threaded upon the metallic putting the invention into effect jacket and bearing upon the outer end of the main bushing, an electrode extending through the core, and a second electrode carried by the main bushing.

2; `In a spark plug, a main bushing, a metallic jacketed core of insulating material introduced into the bushing-from the inner end thereof, said jaeketed core,v having a bearing shoulder limiting the longitudinal movement of the core in relation with the bushing, means for adjust-ing the jacketed core to seat said shoulder firmly upon the main bushing, an electrode embedded Within the core and a second electrode connected with the main bushing.

3. In a spark plu'g, a main bushing, a metallic jacketed core, a bearing shoulder thereon engaging the inner end of the bushn ing, said jacket having a screw threaded extremity, and an adjusting nut engaging the screw threaded extremity of the jacketed core to draw the bearing shoulder thereof into engagement with the main bushing, an

electrode within the core, and a second elec-y trode carried by the main bushing.

4. Ina spark plug, a main bushing having a bearing seat formed in its inner end, a core of insulating material, a reinforcing jacket united therewith, a bearing shoulder on the inner end thereof, and means for adjusting the jacketed core longitudinally to tighten said bearing shoulder upon the bear-- ing seat.

5. An article of manufacture comprising a spark plug core of insulating material, a metallic jacket inclosing said core, a pe ripheral bearing shoulder formed upon said jacket adjacent to the inner or high pressure end thereof,l a head formed upon said core at the inner or high pressure end there of of greater diameter than the jacket and an electrode carried by said core.

(S. An article of manufacture comprising a spark plug core of insulating material consisting of an enlarged head of truncated conical form, and an elongated stem of less diameter than the maximum diameter'of the head, a metallic jacket inclosing said elongated stem and terminating adjacent to said head, and an. electrode carried-by said core.

7. As an article of manufacture, a spark plug comprising a main bushing having a recess in the inner or combustion end thereof, in combination with an inner metallic shell, a shoulder on the inner metallic shell to ft the recess in the bushing, a screw thread on the outer end of the inner shell, a nut thereon, a lill-ing of nonconductive material Within the inner shell, an electrode embedded therein, and a second electrode carried by the bushing.

8. As an article of n'ninufactnre, a spark plug comprising a main bushing counter' a shoulder on the inner or eciiibustioii emi of said shell adapted te i Wiiiii'i the Cmmter bore in said main bushing, lie outei: of the metallic shell beiiigr screw thiemied, an adjusting mit engaging ie Screw threaded end of 'lie metallic Siiel tending eee v- 15o Chim' die shouidei theree into 1he camibeife ei Le "mi hing make a gas igh esimoiiy wheieof l have hereunto se HARY N. ESTIS. Vif/*images ALFRED MCCMY; @ARME M. BECKER, 

